Electric-switch apparatus



'llg. 26, 1930. El A FAGERLUND 1,774,230

ELECTRIC SWITCH APPARATUS Filed Sept. l5, 1928 2 Sheets-Sheet l M' uji W #im w i ff/ 4 z2 4f 7 l y@ Aug- 26, 1930. E: A. FAGERLUND 1,774,230

ELECTR IC SWITCH APPARATUS Filed Sept; 13I 1928 2 Sheets-Sheet 2 Patented Aug. 26, 1930 UNITED STATES PATENT oFFlcE* ERIK ARTUB FAGEBLUND, F STOCKHOLM, SWEDENQ ASSIGNOR 0F ONE-HALF TO HUGO THEODOR TILLQUIST, 0F STOCKHOLM, SWEDEN ELECTRIC-SWITCH APPARATUS Application filed September 13, 1928, Serial No. 305,846, and in Sweden September 16, 1927.

TheJ present invention relates to improvements in such electric switch-apparatus that comprise a plug contact socket in combination with a switch, the latter being operated by means of the plug contact socket. Such apparatus are being especially used in garages and other places where the accumulation of explosive gases is to be feared, and should be of such a character that the said socket is currentless when the corresponding contact plug is inserted or removed so that spark formation and therefrom following risk of explosion is avoided.

The object of the invention is to provide such an apparatus of a simple design at a low cost that at the same time possesses a gasand water-tight arrangement of the switch so that all danger of explosion is removed. The invention also aims at providing an apparatus that is resistant against blows and rough treatment.

The apparatus according to the invention is mainly characterized therein that the contac-t plug after being inserted into the said plug socket is adapted to` make the switch close or open the current when given a turning or swinging motion around its own axis or an axis forming an angle therewith. It is further characterized by a locking device by means of which the said contact plug is prevented from being removed whenV the switch is on. The switch itself may suitably bea turning switch whose movable part 1s electrically and also mechanically `connected with a plug contact socket rotatably arranged in a suitable housing so that the operation of the switch is accomplished by turning said socket after having inserted the belonging contact plug into-the socket.

.A form of a switch-apparatus in accordance with the invention is illustrated by way of example in the accompanying drawings, wherein:

y Fig. 1 shows an elevation of the switchapparatus, partly in cross-section after line Fig. 2 shows a plan view of the same with the contact plug removed.

Fig. 3 shows a cross-section after lined-3 in Fig. 2, and

Fig. 4 shows a plan view ot the contact plug seen from the contact side.

In the illustrated form ot thel invention, 1 designates the hollow housing of the apparatus preferably of cast iron or the like. It

material and upon this layer is arranged a` turning switch of known kind. Said turning switch is provided with a stationary outerpart 7 provided with the usual contacts 5 and 6. The switch consists also of a rotatable inner part 10 provided with the contacts 8 and 9. The contacts 5 and 6 on the stationary part 7 are by means of conductors 11 and 12 connected with contact bars 13 and 14 arranged on the bottom of the housing l. Said contact bars are electrically connected with the incoming cable 15 .(Fig. 2). Said contact bars and the connection with the cable 15 are attached in a pocket 16 arranged at the side of the housing 1. The pocket 16 is suitably filled with insulating material and can be closed gasand wat'er-tightly by means of a cover 17.

To the shaft of the rotatable part 10 of the switch a rectangular block 18 of insulating material is firmly attached. It is provided with contact springs 19-and 20 that by means of conductors 21 and 22 are connected with contacts 8 and 9.on the turnable part 10 of the switch. Said block 18 fits in a corresponding lrecess 23 in a rotatable part of a plug contact socket arranged inside the housing 1. Said rotatable part consists of a metal sleeve 25 provided with an outer flange 24. The sleeve 25'is filled with suitable insulating material 26 in which two sleeve contacts or jacks 27, 28 are attached. Said sleeve contacts or jacks are, as shown in Fig. 1, closed at the bottom and rest with their closed ends against the contact springs 19 and 2O attached in the block 18. The flange 24 of the rotatable plug contact socket 25, 26, 27, 28 rests against the I upper edge or'surface of the housing 1, a packing ring 29 being arranged between them, and

is pressed effectively against said upper edge by means ot springs that act upon balls 30 arranged in the cover 2. By this means an ecient tightening between the cover and the housing is eected that always will remain independent of the wear.

rlhe contact plug (Figs. l, 3 and 4) consists of a wheel-formed handle 3l of insulating material to which is attached a metal sleeve or pipe 32 filled with insulating material 33 in which the plugs 34, 35 corresponding to the contact sleeves or jacks 27, 28 are-attached. Said plugs 34, 35 are in the usual way connected with the outgoing cable 36. The metal pipe 32 is provided with two sidewards directed and diametrically opposite each other arranged tongues or projections 37 provided with pins 38 adapted to fit into corresponding holes in the iiange 24 when the plugs 34', 35 are inserted into the jacks 27, 28 so that when turning the contact plug 3l, 32, 33 also the socket 25, 26 will be turned, and thus by means of the block 18 also turn the rotatable part ot the switch.

In the cover 2 a central hole for the cylindrical part 32 o the contact plug is provided, and further two diametrically opposed recesses 39 into which the projections or tongues 37 on the pipe 32 can be entered. Further on the inside of the cover 2 there are provided stops 40 against which the projections 37 will rest after the turning motion ot the contact plug.

ln the position shown in the drawings of the rotatable part 25-28 of the switch in relation of the recesses 39 in the cover 2, the contact plug 31-35 can be inserted into the socket 25, 26. rlhe switch is then off and thus the jacks or sleeves 27, 28 are currentless. rliherefore, no spark formation can occur at the insertion of the contact plug. At the following turning of the contact plug together with its socket 25, 26 the block 18 will also be turned and thus the switch put in circuit. Occasionally in the switch occurring spark formation will be of no importance on account of the gas-tight arrangement of the switch. At the mentioned rotation of the socket 25, 26 the said protruding projections 37 of the plug will be located inside the cover 2 and rest against the stops 40, as shown in llig. 2 with dashed and dotted lines. In this position when the current is on as stated above, it is apparent that the contact plug cannot be removed, wherefore no spark torroation can occur. To make the removement ot the contact plug possible the same together with the socket 25, 26 must be turned back to the initial position where the projections 37 are in alignment with the recesses 39 in the cover. During this turning motion however, the switch is cut out so that when the contact plug thereafter is removed, the jacks 2'7, 28 will be currentless and thus the danger of spark formation eliminated.

llt is apparent that the invention is not 11mited only to the form illustrated in the drawings. Thus, for instance, the switch may consist of a common push 'button switch, in which case the rotatable plug contact socket 25, 26 may be provided with projections or the like having inclined surfaces that when turning the said socket cooperate with the push buttons of the switch so that the latter, dependent ot the direction of rotation, either closes or opens the circuit. Alternately the whole may be so arranged that the switch is operated by swinging the contact-plug, for instance about an axis perpendicular to its own axis.

l claim zl. Electric switch apparatus comprising a housing, a turning switch arranged in said housing, a rotatably arranged plug contact socket, a contact plug for said socket, means tor electrically connecting the rotatable part of said switch with said socket, means for mechanically connecting said rotatable part of said switch with said socket, a flange being provided on the socket adapted to close the open end of said housing, a cover for the housing, springs arranged in said cover so as to keep said liange continually pressed against said housing for tightening purposes.

2. Electric switch apparatus comprising a housing, a turning switch arranged in said housing, a rotatably arranged plug contact socket, a contact plug for said socket, means i'or electrically connecting the rotatable part ot said switch with said socket, means for mechanically connecting said rotatable part of said switch with said socket, a flange being provided on the socket adapted to close the open end of said housing, a cover for the housing, balls arranged between said cover and the top of said flange, springs arranged in said cover so as to press said balls against said flange and keep the flange continually pressed against said housing for tightening purposes.

3. Electric switch apparatus comprising a housing, a turning switch arranged in said housing, a rotatably arranged plug contact socket, a contact plug for said socket, means ior electrically connecting the rotatable part ot said switch with said socket, means for mechanically connecting said rotatable part of said switch with said socket, a iiange being provided on the socket adapted to close the open end of said housing, a packing ring between said flange and the housing, a cover for the housing, springsv arranged in said cover so as to keep said flange continually pressed against said housing for tightening purposes.

4. Electric switch apparatus comprising a housing, a turning switch arranged in said housing, a rotatably arranged plug contact socket, a contact plug for said socket, means for electrically connecting the rotatable part of said switch with said socket, means for mechanically connectin said rotatable part of v said switch with sai socket, aange being provided on the socket adapted to close the open end of said housing, a packing ring between said flange and the housing, a cover for the housing, balls arranged between said 

